Method of coating surfaces with a hard covering



Patented Sept. 9.1930

UNITED, STATES JOEAH AXE]:- GUSTAISSON, OI NOBBTAHE, SWEDEN IE'IfiOD OI OOATING SURFACES WITH A HARD ms mung. Application and lay a1, 1929, Serial 10.867319, and in sweden larch a, 1m.

This invention relates to a method of coating surfaces with a hard covering which is weather-proof and resistive to in urious action and can be made in any colour desired.

5 Theinvention consists chiefly, in coating the surface with a ground layer of glue insoluble in water, overstrewing with a mineral powder and, after drying, coating with filling mass, which consists of a drying oil and a watery solution of an adhesive as well as'a suitable quantity of a fine-grained mineral powder. After drying a. very resistive, weather-proof covering is attained. Preferably, the surface is beforehand grounded with such glue of thin consistency insoluble in water, said glue being left to dry completely before the other substances are applied. The

filling mass mentioned above may also contain a pigment. 10 It is, of course, well known to use mineral matter in such coatings, but a characteristic feature of the'present invention is the composition of' the adhesives used to bind the mineral material.

In one preferred embodiment of the invention one or more layers of nitrocellulose 'or pyroxylin lacquer are applied on the surface, in combination with colour coatings for decoration, if desired. g When carrying out the method practically, for instance in treating a wooden surface, the surface is firstl rimed or grounded with thin glue inso u la. in water preferably casein lime glue, which is left to aground layer of such Inc of a t cker consistency is applied 8.1M? (quartzsand) immediately-siftedon. Forcertam (purposes coarser sea sand emery or glass pow er or other mineral powder may be used instead of the fine seasand. If the sand is sifted on a horizontal surface the latter is afterwards raised to a vertical position thus causing all su rfluous sand to fall oil, so that a layer 0 suitable thickness uniformly distributed over the whole surface willie- ,main. The superfluous sand is gathered to V V be used again. a

. When carrying out themethod on a large scale in factories the glue is, preferably, ap-

ll l' plied by means of a suitable glue applying ,and then fine white seasandl machine, for. instance having felt rollers, and the sand oi powder is sifted on b means of'a mechanically driven' siftingdevice.

This ground layer of sand and glue having dried thoroughly, an emulsion or g mass is applied, which is ground and mixed in a aint mill and consists of a drying oil, for instance boiled linseed oil, and a watery solution of paste, (preferably wheat flour paste) glue, casein, lime, in, glair or the like toco gether with a suitable quantity of finegrained uartz powder and, if desired, a pigment. he watery solution of paste etc. on one hand and the drying oil on the other hand are preferably used in equal partsin the emule6 sion, but the relative quantity of oil may also be less. It has been found, that alsoan emul-- sion containing paste and oil in the proportion of 2:1 may quite well beused. Instead of the quartz powder a fine-grained powder of glass, emery, marble, gypsum, heavy-spar or other similar mineral material ma be used. As a pigment zinc oxide or other h htproof and air-proof materials of the desired colour' are used. A cheap and effective pigment is heavy-spar coloured with aniline colours. a

This emulsion or filling mass has the double purpose of filling out the spacebetween the grains of sand in the underlying layer of glue to give an even, smoothsurface and of protecting against the action of moisture and temperature.

When carrying out the method on a large scale in factoriesthe filling mass is, referably, applied by means of a machine aving brush rollers. .1

which can be The coating thus attained 7 made in any colours desired and also be veined, marbled etc. in well-known manner, can without any further treatment be used for many different. purposes. If a further treatment of the surface is made or if the appearance is of no imqgrtanc'e the pigment m thefilling mass may dispe Wlth.

' If a more decorative surface resistive to much moisture, l 0, sea spirits, ammonia etc. is necessary t e an ace produced in the manner described above is coated with one or more layers of nitrocellulose or pyroxylin side-and,

lacquer. If the surface is to be decorated in a special manner, for instance by veining, marbling, decorative painting etc. such decoration 1s, preferably, made between two thin layers of coloured or colourless nitrocellulose lacquer. To vein and marble the usual pigments for such purposes may be used, such as terra sienna, van Dyke-brown, boneblack etc. For use the pigments are mixed either with skimmed milk (casein solution) or in certain cases with a turpentine oil paint of low percentage of oil.

The coating of pyroxylin lacquer on the sand ground described becomes extremely hard and. resistive. The surface resembles a stone or a dressed brick wall surface and has a hardness approaching that of said materials. It has been found that quer on other ground does not by far give the same good result. The pyroxylin lacquer is, preferably, sprayed on by means of an air rush or paint sprayer of usual design.

The method according to theinvention may advantageousl be used for treating wood surfaces of a l(inds as well as other surfaces, and is particularly adapted to make plywood resistive to injurious action. The surfaces of the plywood sheets may for this purpose be treated in the factory so that only a treatment of the joints is pecessary, when the sheets are set up.

The plywoodsheet is coated on the front side as well as on the back side with glue and sand and with the filling mass and is thus prevented from warping and completely pro: tected against moisture. Moreover, the front if the sheet is to be set up in a place, where it will be exposed to very strong injurious action, also the back side-may be treated with pyroxylin lacquer. The pl wood sheet thus treated may, in spite of t 0 great hardness of the coating, be bent to some extent without thus damaging the coating and ma be worked by stance :sawed, if a score is before cut through the hard coating down to the wood. To fasten the sheets with' nails or screws a counter-sink for the nail or screw head is made in the hard ,coatin' c On plywood or other sieets to be used for lining large surfaces on walls, ceilings or {floors a margin about 1 cm. wide round the {slits bevisible.

edges of the sheet is left without coating. After the sheets have been set up this margin A as the remaining portion of the surface, i. e. glue and sand are applied, filling mass 1s spread over, etc. Inthis manner also very largesurfaces may .pl ood sheets and yet no 7 'Flib Ijloints may, however, covered -with laths a .a coating according to the invention. Surfaces already set up,for instance, usual wooden walls may, of course, also be treated according to the invention, though it is generally more advanbe-; covered with pyroxylin lacmeans of tools, for in-- tageous, from an economic point of view, to make the coating in the factory.

The method according to the invention renders it possible to use wood for a plurality of purposes for which it has been less adapted heretofore, for instance, for linings for bathrooms and linings resistive to the action of weather for outside walls etc.

It is, of course, possible to use for the water-proof glue another gluing substance which per se is soluble in water, such as animal glue, gelatine and the like and after its apphcation treat it with a hardening substance, such as formaldehyde.

What I claim is 1. A method of coating surfaces with hard covering, comprising coating the surface with a ground layer of glue insoluble in water, overstrewing with a mineral powder, and, after drying, applying a filling mass consisting of a mixture of a drying oil, a watery solution of an adhesive and a finegrained mineral powder.

2. A method of coating surfaces with a hard covering, comprising coating the surface with a ground layer of glue insoluble in water, overstrewing with a mineral powder, and, after drying, applying a filling mass consist' of a. mixture of a drying oil, a watery so ution of an adhesive, a fine-grained mineral powder and a pi cut.

3. A method of coatmgsurfaces with 'a hard covering, comprising coating the surface with a ground ayer of glue insoluble in water, overstrewing with a mineral powder, after drying applying a filling mass consisting of a mixture of a drying 011, a watery solution of an adhesive and a fine-grained mineral owder, and, after drying, applying py- 'roxy n lac uer.

4. A met 0d of coating surfaces with a hard covering, com rising coating the surface with a ground ayer of glue insoluble in water, overstrewin with a mineral powder, after drying applymg a filling mass consisting of a mixture of a drying 011, a watery solution of an adhesive and a fineained mineral powder, and finally applylng pyroxiylin lacquer in several layers with mterme iate la ers of colouring substance.

5. method of coating surfaces with a hard covering, comprising ounding the sur-' face with thin glue insolu l e in water, after drying coating the surface with a round layer of such glue of a thicker conslstency, overstrewing with a mineral powder and, after'drying, applying a filling mass consisting of a mixture, of a drying oil, a watery so utionof an adhesive and a fine-grained mineral powder.

6. A method of coating surfaces with a hard covering, com rising coating the surface with a ground liiyer of glue insoluble in water, overstrewing with a mineral powder and, after drying, applying a filling mass ing with fine quartz sand, after dryin consistin of a drying oil and a watery solution 0 'an addition of a fine-grained mineral powder,

an adhesive in. equal parts with 7. A method of coating surfaces with a hard covering, comprising grounding the surface with thin casein lime glue, after drying coating it with'a ground layer of casein lime glue of a thicker consistency, overstrewl mg a filling mass, consisting of 1001 ed 11nseed oil and a watery solution of glue in equal parts with an addit1on of fine-grained quartz sand, and finally applying pyroxylin lacquer in several layers with intermediate layers of colouring substance.

In testimony whereof I have signed my nam JOHAN 'AXEL GUSTAFSSON. 

